1. Technical Field
The present innovations relate to cooling technology, and more particularly to thermoelectric coolers implementing the Peltier effect.
2. Description of Related Art
As the speed of computers continues to increase, the amount of heat generated by the circuits within the computers continues to increase. For many circuits and applications, increased heat degrades the performance of the computer. These circuits need to be cooled in order to perform most efficiently. In many low end computers, such as personal computers, the computer may be cooled merely by using a fan and fins for convective cooling. However, for larger computers, such as mainframes, that perform at faster speeds and generate much more heat, these solutions are not viable.
Currently, many mainframes utilize vapor compression coolers to cool the computer. These vapor compression coolers perform essentially the same as the central air conditioning units used in many homes. However, vapor compression coolers are quite mechanically complicated requiring insulation and hoses that must run to various parts of the main frame in order to cool the particular areas that are most susceptible to decreased performance due to overheating.
A much simpler and cheaper type of cooler are thermoelectric coolers. Thermoelectric coolers utilize a physical principle known as the Peltier Effect, by which DC current from a power source is applied across two dissimilar materials causing heat to be absorbed at the junction of the two dissimilar materials. Thus, the heat is removed from a hot substance and may be transported to a heat sink to be dissipated, thereby cooling the hot substance. Thermoelectric coolers may be fabricated within an integrated circuit chip and may cool specific hot spots directly without the need for complicated mechanical systems as is required by vapor compression coolers.
However, current thermoelectric coolers are not as efficient as vapor compression coolers requiring more power to be expended to achieve the same amount of cooling. Furthermore, current thermoelectric coolers are not capable of cooling substances as greatly as vapor compression coolers. Therefore, a thermoelectric cooler with improved efficiency and cooling capacity would be desirable so that complicated vapor compression coolers could be eliminated from small refrigeration applications, such as, for example, main frame computers, thermal management of hot chips, RF communication circuits, magnetic read/write heads, optical and laser devices, and automobile refrigeration systems.
Typical thermoelectric coolers also are formed in a top-down fashion, where the thermoelectric elements are disposed vertically with a cold conducting section (the heat source) on (for example) the bottom of the system, and the hot conducting sections (correspondingly) on the top of the system. Such cooling systems are complicated to fabricate and occupy large volumes.
The present innovations teach improvements to thermoelectric heating technology. In a preferred embodiment, a thermoelectric cooler system is constructed in the lateral or horizontal direction (as opposed to vertically) having a plurality of pointed tips that serve to contact a thermoelectric material with a conductor. In a preferred embodiment, the thermoelectric elements and the conducting sections to which they connect all substantially occupy the same plane, making the devices smaller than vertically disposed or formed cooling systems. The points on the thermoelectric material are formed preferably using focused ion beam techniques or electron beam lithography. In other preferred embodiments, arrays of such thermoelectric cooling devices are fabricated, to cool nanoscopic regions of various shapes and cooling needs.